Part 1 – Introduction and background Part 2 - Aerial photographs illustrating various ice conditions Part 3 - River PIREP format and terminology Part 4

Part 1 – Introduction and background

Part 2 - Aerial photographs illustrating various ice conditions

Part 3 - River PIREP format and terminology

Part 4 - Tips on taking aerial photographs of river ice

http://aprfc.arh.noaa.gov/rivwatch.php

RIVER WATCH PROGRAM

• Purpose of program is to assist the NWS in providing accurate forecasts, warnings, and river navigation information

• A voluntary program asking pilots and other individuals to report observed river conditions

• Requesting observations that can be obtained without deviation from the normal route or flight level

• Standard method of reporting is to submit pilot report to FAA’s Flight Service Stations by radio

• Other reporting options are phone, emailing report and/or digital photos, and filling out a web form

BACKGROUND

• National Weather Service (NWS) monitors ice breakup conditions throughout Alaska to assess flood threats and navigational hazards

• Other monitoring capabilities leave large voids in the knowledge of river and lake ice conditions…

A monitoring program conducted in conjunction with Alaska Division of Homeland Security and Emergency Management in chartered aircraft is only done in specific locations when flood threat is high

Observers in villages along rivers provide a ground based view only in front of their village

Satellite images provide some broad information on larger rivers, but lack the resolution to fully understand the ice conditions

• Supplemental aerial observations from aircraft flying at lower altitudes have significantly enhanced the spatial and temporal coverage of information on ice characteristics

2005-7 RIVER WATCH PROGRAM

The first year of the program targeted Fairbanks FSS, air taxi operators, and private pilots

The 2006 program expanded into southwest and southcentral Alaska

The 2007 program continued to expand its coverage statewide

2009

Spring 2009 breakup along the Yukon and Kuskokwim River resulted in the most destructive flooding in many decades. Communities made preparations to deal with high water and major flooding based on NWS Warnings which were issued due to observational information gathered from PIREPs during River Watch flights.

FEEDBACK - COMPILATION OF OBSERVATIONSFollow progress of breakup on Alaska Weather on PBS or on web

http://aprfc.arh.noaa.gov/

Observations of ice conditions on these or any Alaska rivers and lakes are needed

The progress of breakup is displayed

on the web graphically along with text

reports and selected recent photos.

Pilot reports are used to provide more accurate information on this map.

FEEDBACK - SEARCH REPORTS ON WEBhttp://aprfc.arh.noaa.gov/php/rivnotes/searchnotes.php

Anyone can search our river notes database for pilot or other reports of river ice conditions by river, location, or view all reports or only PIREPs

TRAINING RESOURCES

Program web site…


Feel free to request group training from your NWS contact

CONTACT INFORMATION

River Forecast Center (ANC) – Scott [email protected] 266-5152

Service Hydrologist (FAI) – Ed [email protected] 458-3714

Aviation Focal Point (FAI) – Brad [email protected] 458-3713


mailto:[email protected]



Part 2 - Aerial photographs illustrating various ice conditions

• Breakup process varies somewhat with river size and with latitude in Alaska

• Great variability is common in ice conditions… the objective in the river PIREP is to report the predominant condition or use qualifiers (ocnl, few, mostly, etc)

Aerial photographs courtesy of APRFC staff, partner agencies, and participating commercial and private pilots

Breakup Timing

PRE-BREAKUP CONDITIONS

• Unbroken ice – continuous ice surface that has few if any cracks • Arched ice – ice that is attached to the banks, which rises in the

center of the channel due to increased flow beneath the ice causing melt water to collect in channels along the banks

• Lifted ice – ice that has broken from the banks and is floating on the river water, but is not moving; usually has river flow along both sides

• Shifted ice – large ice sheets that have moved short distances from their original locations as rising water levels create wider areas of open water into which the ice can move

• Open reach – a length of river channel with no ice that results from ice shifting a short distance down river

•Open lead - A narrow channel of open water in the ice•Snow on ice – snow on the ice surface that appears white from the air•Clr water on ice – snow on the ice surface that is melting and forming pools of water•Hard ice – strong ice that appears white, blue or green•Rotten ice – weak ice that appears black or brown

Primary sequential phases of the pre-breakup process:

Other characteristics that may be observed combined with a phase:

UA/…/RM YUKON RIV HARD UNBKN W/ SNOW ON ICE

/OV format – Point or Segment

Unbroken ice – continuous ice surface that has few if any cracks

UA/…/RM YUKON RIV ARCHED ICE

Arched ice – ice that is attached to the banks, which rises in the center of the channel due to increased flow beneath the ice causing melt water to collect in channels along the banks/OV format – Point or Segment

UA/…/RM YUKON RIV UNBKN MOSTLY ROTTEN ICE

Rotten ice – weak ice that appears black or brown


UA/…/RM YUKON RIV LIFTED AND ROTTEN

Lifted ice – ice that has broken from the banks and is floating on the river water, but is not moving; usually has river flow along both sides


UA/…/RM YUKON RIV HARD LIFTED AND SHIFTED SHEETS

Shifted ice – large ice sheets that have moved short distances from their original locations as rising water levels create wider areas of open water into which the ice can move/OV format – Point or Segment

MOVING ICE CONDITIONS

• Breakup front – location along river between moving ice and stationary ice

• Ice run – a continuous length of moving ice that may be up to 10’s of mi in length; typically grades from large ice pieces at downstream end to small ice pieces at upstream end

• Ice sheets – large pieces of ice with length greater than width and width > 50% of river width

• Ice pans – pieces of ice that are 10 to 50% of the river width in size

• Ice chunks – small pieces of ice that are <10% of the river width in size

UA/…/RM YUKON RIV BREAKUP FRONT

/OV format – Point only

Breakup front – location along river between moving ice and stationary ice

ICE BREAKUP FRONT• Breakup date and time is when breakup front passes a

location• Flood threat due to an ice jam is greatest just after

breakup front passes village• Can be difficult to differentiate between breakup front

and an ice jam

The ice breakup front can move down river like an inchworm… the front may stall out temporarily to wait for the back end to catch up… this would not be called an ice jam

Look for a significant amount of the ice run packing in up river from the location where the breakup front stopped… this would be an indication of an ice jam

TYPICAL RUN OF ICE

May be 10-20 miles in length

Reach of large moving sheets (nr breakup front)

Reach of mixed sheets, pans, and chunksReach of mostly chunksSubsequent runs are mainly chunks

UA/…/RM YUKON RIV HVY MXD RUN


Ice run – a continuous length of moving ice

UA/…/RM YUKON RIV HVY RUN MOSTLY CHUNKS BTWN RBY-GAL



UA/…/RM YUKON RIV HVY 8 MILE LONG ICE RUN

Note that a HVY ice run up river looks MOD in this wider reach of river



ICE JAM CONDITIONS

• Ice jam – an ice run that has stopped moving due to any of a variety of reasons; characterized by a long reach of tightly packed chunk ice

• Ice jam flood – water spreading over the banks up river from an ice jam

• Village flood – water spreading into a village that covers roads or threatens buildings

• Widespread flooding – water that has gone over the banks and covered vast areas of land that are normally dry

BREAKUP JAM

Forms when breakup front encounters a competent ice sheet or constrictionMay be surface, thickened, or hanging,

depending on speed of ice movementFlood threat upstream varies with type of

jamStream level can increase very rapidly

upstream of a jamFlood threat is greatest just after breakup

front passes village

UA/…/RM YUKON RIV BISHOP ROCK UNBKN; MELTING SNOW ON ICE

Historic ice jam problems at Bishop Rock on Yukon and below Aniak on Kusko

This pre-breakup photo shows the wide ice surface in the foreground that will have to go around the bend and through the narrow opening at Bishop Rock

UA/…/RM YUKON RIV BISHOP ROCK APPARENT ICE JAM

/OV format – Point only

Ice jam – an ice run that has stopped moving due to any of a variety of reasons; characterized by a long reach of tightly packed chunk ice

ICE JAM THREAT LOCATIONS

• Ice jams can occur at any location• Historic ice jam problems at Bishop Rock on

Yukon and below Aniak on Kusko• Threats also associated with ice conditions at

and up to 10 miles down river from… Eagle, Circle, Fort Yukon, Galena, Koyukuk, Nulato,

Russian Mission, Pilot Station, and delta villages on the Yukon

McGrath, Sleetmute, Red Devil, Crooked Creek, Akiak, Kwethluk, and Bethel on the Kusko

Kobuk on the Kobuk and Buckland on the Buckland

ICE JAM IMPACTS

Upstream from the jam...

Fast water level risePacked ice chunksPotential flooding

UA/…/RM KUSKO RIV ANI VILLAGE AND RWY (10% USABLE) FLOODING


Village flood – water spreading into a village that covers roads or threatens buildings

UA/…/RM YUKON RIV WIDESPREAD FLOODING

Widespread flooding – water that has gone over the banks and covered vast areas of land that are normally dry/OV format – Point or Segment

POST-BREAKUP CONDITIONS

• Stranded ice – ice pushed onto the banks or into side channels that is left behind after the ice has cleared out of the main channel

• Open channel – no ice in the main channel of the river

• Ice or debris run – a length of river channel containing moving ice or debris (trees, brush, etc) that is further categorized by amount…

Light run – <25% of surface coveredModerate run – 25 – 75% of surface coveredHeavy run – >75% of surface covered

UA/…/RM YUKON RIV MOD ICE RUN HVY STRANDED ICE ON SHORE

Ice or debris run – a length of river channel containing moving ice or debris (trees, brush, etc)


UA/…/RM YUKON RIV LGT ICE RUN

Ice or debris run – a length of river channel containing moving ice or debris (trees, brush, etc)/OV format – Point or Segment

UA/…/RM KOYUKUK RIV OPEN HVY STRANDED ICE ON SHORE

Stranded ice – ice pushed onto the banks or into side channels that is left behind after the ice has cleared out of the main channel


UA/…/RM KOYUKUK RIV OPEN MOD STRANDED ICE ON SHORE

Stranded ice – ice pushed onto the banks or into side channels that is left behind after the ice has cleared out of the main channel


Part 3 - River PIREP format and terminology

• Pilots are familiar with pilot reports (PIREPs) for documenting weather impacts to flight

• River PIREPs supplement a normal PIREP with observations of notable or changing conditions on a river

• Although river PIREPs can be given at any time of year for any condition, the initial emphasis concentrates on ice breakup observations

• Lake ice information can also be included in a river PIREP but must still include RIV in remark

PIREP FORMAT

• UA or possibly UUA for severe flood report• /OV - Point or route segment format• /TM – UTC time of event observed• /FL – Assists weather evaluation and observation resolution• /TP – Assists weather evaluation• /SK – Assists weather evaluation• /WX – Assists weather evaluation• /TA – Assists weather evaluation• /WV – Assists weather evaluation• /TB – Assists weather evaluation• /IC – Assists weather evaluation• /RM – Heart of the river report

Items highlighted in red are considered to be the most important part of the PIREP for use in river ice assessments but weather reports are encouraged

/OV – LOCATION FORMAT

• Point format (e.g. /OV MCG18030) is useful to describe specific location of an ice feature such as breakup front, ice jam, downstream end of ice run or flooded village

• Segment format (e.g. /OV SRV-SLQ) is useful to describe ice or flooding conditions along a reach of river

• Optional format to specify river mile in the remark section (maps w/river miles for some rivers available on program web site)

/RM - REMARK FORMAT

• /RM name RIV description, where…name is the name of the river or lakeRIV is a key identifier for the NWS and

must be included even if it is observations of lake ice

description is an abbreviated description of the observed ice conditions

For Example….FAI UA/OV GAL270013/TM 2355/FL060/TP C207/RM YUKON RIV BISHOP

ROCK APPARENT ICE JAM

STANDARD RIVER PIREP REMARKS

GENERAL• UNBKN• ARCHED• LIFTED• SHIFTED• OPEN

PRE-BREAKUP CONDITIONS

SUPPLEMENTAL• HARD• ROTTEN• SNOW ON ICE• CLR WATER ON ICE• MUDDY WATER ON ICE• OPEN HOLES• OPEN LEADS• FLOW IN SIDE CHAN• FLOW ON ICE

GENERAL

• BU FRONT• ICE RUN…

MIXEDSHEETSPANSCHUNKS

• X MI ICE RUN (LENGTH = X)

STANDARD RIVER PIREP REMARKS MOVING ICE

ICE RUN DENSITY

• HVY (>75%)• MOD (25-75%)• LGT (<25%)

STANDARD RIVER PIREP REMARKS

ICE JAMS

•APPARENT ICE JAM

•ICE JAM

ICE JAM AND FLOODING CONDITIONS

FLOODING

•VILLAGE NAME FLOODING

•RWY FLOODING (% USABLE)

•WIDESPREAD FLOODING

•LOW-LYING FLOODING

ANY QUESTIONS????

Part 4 - Tips on taking aerial photographs of river ice

Prepared by Tom GeorgeAlaska Regional Representative

Aircraft Owners and Pilots Association

Overview

• Tips on taking pictures

• Transmitting pictures via e-mail to the River Forecast Center

Tips on photographing

• Don’t wear bright clothing which may reflect in the windows of the aircraft

• Keep upper body away from airframe to avoid transmitting vibrations to the camera

• Use a high shutter speed to avoid image motion• If possible, open the aircraft window to improve

the quality of the images—check with the pilot first!

• Use an intercom system to aid communications between pilot and photographer

Sun Direction

When photographing into the sun, “forward scattering” tends to enhance haze and obscure ground features.

Sun directionSun direction

Shooting “down sun” minimizes haze, resulting in a sharper image.

Glare and reflections

Shooting through curved windshields generally results in glare and reflections. Shooting through flat side windows, or opening the window gives the best results.

Setting up the picture

• Identify the feature you plan to photograph•Consider the lighting•Consider the best angle to show the feature•Position the aircraft relative to the target

–Typically, behind the strut on the photographer’s side of the aircraft

•Take the photograph•Record the location, time and other significant features:

–Ice type, jam, flooding, etc.

Flooding impact

Water outside the channel

Wait for the target…

Too far to see detail Good detail and reference locations

Target area

Focal length of camera

• Use wide angle lens to show larger area

• 35 mm lens on a 35 mm film camera

• Easier to:

-See the “big picture”

-Identify land marks

Wide angle shot

Zoomed in telephoto image

• Generally better to shoot up or down stream

• Cross stream is harder to:

-Establish location

-See ice details

Viewing angle

Flight altitude

• ~3,000 feet above ground level is a good altitude for general observations

• Lower shows more detail, but a lot less area

• Higher is some times useful to show the “big picture”

Example: Tanana River, looking upstream, into the sun, from ~3,000 feet agl.

Example: Confluence Chena and Tanana, down sun, ~3,000 feet agl.

Transmitting digital pictures to NWS River Forecast Center

• Images and text transmitted via e-mail:• Image size ~ 7 x 10 inches, 100 pixels/inch• Jpeg, factor 8 – 10• Compresses to image size of ~200K• If sending many images, may need to spread across

several e-mail messages due to 20MB limit

Send to: River Forecast [email protected]

Or call: (800) 847-1739


Thanks for your help


Documents

Part 1 – Introduction and background Part 2 - Aerial photographs illustrating various ice conditions Part 3 - River PIREP format and terminology Part 4